After you have a certified unit in the system, you can maintain calibration of your Thermo Scientific™ Model 81i Mercury Calibrator in the field. Utilize the method outlined in the Advanced Instrument and System Calibrations technical bulletin to extend the calibration time period.
Most Popular Tips and Tricks
Volume III, Edition 9
Thermo Fisher Scientific has been delivering the Fast5 newsletter to you for almost three years. In this issue, we share a list of the top five tips & tricks from our most popular issues:
Maintain calibration in the field
Make the right choice
Choosing the proper converter on your Thermo Scientific™ Model 42i series of gas analyzers will have an effect on performance and operation. Depending on your application, you have two converter options: a stainless steel converter and a molybdenum (also known as "moly") converter.
Moly converters are used primarily in ambient applications where the NO2 concentrations are typically less than 100 ppb. They can be used in source applications when you have low O2 concentrations of less than 3% and low NO2 concentrations of less than 1 ppm. Moly converters typically have a life of about 20,000 ppm hours of NO2.
On the other hand, stainless steel converters are not recommended in ambient applications because they operate at very high temperatures (625° - 635°C) which could break down gases like ammonia, resulting in false readings. Stainless converters are used in almost all source applications except those with very low O2 levels. When using a stainless steel converter, your sample must have an oxygen concentration of 3% or greater otherwise the oxide layer gets stripped over time and it stops converting NO2 to NO.
Optimize removal of CO from dilution air
The best engineering practice for removing CO from dilution air on your Thermo Scientific™ Model 43i SO2 Analyzer is to use a palladium catalyst, which converts CO in the instrument air into CO2 before using it as the dilution air.
How do you ensure the palladium catalyst is performing properly? Make a comparison of three different responses of the Thermo Scientific Model 48i CO Analyzer:
1. Send bottled Nitrogen directly into the analyzer and record the result.
2. Send bottled Nitrogen up to the dilution probe and use it as a zero gas and record the result.
3. Send clean, palladium-scrubbed air directly to the analyzer and bypass the dilution probe.
If different results are obtained between these 3 tests, use this data to aid in troubleshooting
Set up a pre-calibration check
Prior to putting your Thermo Scientific™ Model 43i SO2 Analyzer into service or performing the final compliance calibration, you may want to perform a pre-calibration of the unit. Thermo Scientific Model 43i SO2 Analyzer series pre-calibration procedures are specific to the individual model. Click on the link below for your specific model’s setup procedure:
Thermo Scientific™ Model 43i SO2 Analyzer Pre-Calibration
Thermo Scientific™ Model 43i-HL High Level SO2 Analyze Pre-Calibration
Thermo Scientific™ Model 43i-TLE Trace Level SO2 Analyze Pre-Calibration
Maximize on-board diagnostics
Using the iPort software, the onboard software interface for Thermo Scientific™ iSeries gas analyzers, a great deal of information concerning system performance is accessible. Many operators use this data for troubleshooting, however if you decide to contact Technical Support, the iPort software records (commonly referred to as LRECs) are good to have on hand.
To download the data records, follow these steps:
1. Go to Preferences and check Raw Flags
2. Go to Instrument from the main menu and select Load Records
3. Select number of records and select Long Records
4. Make sure to check the "Save to File" checkbox
5. Click OK